Dental impression-cup.



, I Patented A H. D. 0SG00 "9 28,490

DENTAL IMPRESSION CUP.

(Application filed Jan. 9, 1900-) (No Model.)

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Unirrnn STATES PATErrr OFFICE.

HERMAN D. OSGOOD, OF CONCORD, MASSACHUSETTS.

DENTAL IMPRESSION-CUP.

SPECIFICATION forming part of Letters Iatent No. 657,002, dated August 28, 1900.

To ctZZ whom it may concern:

Be it known that I, HERMAN D. Oseoon, of Concord, in the county of Middlesex and State of Massachusetts,have invented certain new and useful Improvements in Dental Impression-Cups, of which the following is a specification.

This invention relates to appliances used by dentists in taking an impression of the roof of the mouth and the adjoining parts.

The invention has for its object to provide a cup adapted to retain the plaster displaced while the impression is being taken, thus preventing the displaced plaster from falling into the throat of the patient, and capable of being easily taken apart to be cleaned.

The invention consists in the improvements which I will now proceed to describe and claim.

Of the accompanying drawings, forming a part of this specification, Figures 1 and 2 represent plan views of the parts of a dental impressioncup embodying my invention, the parts being separated. Fig. 3 represents a longitudinal section through the center of the cup, showing the parts connected and a confining strip or dam in place. Fig. 4 represents a section on line 4 4 of Fig. 1. Fig. 5 represents a section on line 5 5 of Fig. 2.

The same reference characters indicate the same parts in all the figures.

My improved cup comprises two general parts-namely,a body portion ,which includes a bottom plate a and a U-shaped flange rising from the margin of said plate, as shown in Figs. 1 and 4, and an arched plate having its margin formed to fit the inner surface of the flange a, said plate including the flat or seat portion a adapted to rest on the bottom plate a of the body of the cup, and the arched port-ion a which is formed to approximately fit the roof of the patients mouth. The arched portion a is struck up from the body of the blank from which it is made, said arched portion having no bottom. A flange b is formed on one end of the arched plate, said flange filling or nearly filling the opening between the ends of the flange a when the twoparts are assembled.

The flange a is provided with a series of inwardly-projecting pins or lugs 0 which project over the bottom plate a and are in position to bear upon the upper edge of the marginal portion a of the arched plate when the two parts are assembled, the pins holding the marginal portion of the arched plate in close contact with the bottom plate a. The arched plate has an opening a, which when the parts are assembled forms the mouth of a cavity or chamber adapted to receive the surplus plastic material used in making an impression of the roof of the mouth, as described in Letters Patent of the United States No. 637,480, granted to me November 21, 1899. A vent-hole dis formed in the bottom plate a and communicates with the said chamber or cavity, its object being to permit the air in said chamber to be displaced by the plastic material which enters the chamber, thus permitting the plastic material to freely enter the chamber.

When the device is used, the arched plate is placed upon the bottom plate a, and a dam b is formed by placing a strip of wax or other suitable material against the inner side of the flange b, said strip extending outwardly beyond the ends of the flange a. The pins 0 hold the arched plate down upon the bottom plate ct; but, if desired, this may be supplemented by small pieces of Wax placed, when melted,in the angle formed by the flange a and the marginal portion of the arched plate, thus holding the latter securely. The cup is then used as described in my former patent. After its use the dam b is'removed, and the two parts are separated, so that all portions of the surfaces may be easily cleaned.

I claim- 1. A dental impression-cup composed of a body portion having a bottom plate and a U-shaped flange, and an arched plate having a seat formed to bear upon the-bottom plate of the body.portion and a flange formed to cooperate with the ends of the U-shaped flange, said arched plate having an opening which forms the mouth of a chamber or cavity when the two parts are assembled, the said parts being separable.

2. A dental impression-cup comprising a body portion having a bottom plate, a U- shaped flange, and pins or lugs projecting inwardly from the flange over the bottom plate, and an arched plate having a marginal portion formed to bear upon the said bottom plate and engage the said pins, said arched flange and an opening which constitutes the 16 plate having a flange and an opening, submouth of said cavity. stantially as described. In testimony whereof I have affixed my sigb 3. A dental impression-cup comprising a nature in presence of two Witnesses.

ottom plate having a vent-opening and a U-shaped flange, and an arched plate coop- HERMAN OSGOOD erating with said bottom plate in forming a Witnesses: chamber or cavity Which communicates with W. F. WINCHESTER, the vent-opening, said arched plate having a C. F. BROWN. 

